Inherited from Sauraseni Prakrit *𑀮𑀲𑁆𑀲𑀻 (*lassī), likely from 𑀮𑀲 (lasa, “stickiness”) (whence Hindi लस (las)), from Sanskrit लश (laśa, “gum, resin”)
لسی • (lassī) f (Hindi spelling लस्सी)